Field of the Invention
The present invention relates to a battery temperature regulating device, and in particular, relates to a battery temperature regulating device mounted on a vehicle including a battery configured to allow charging from a power supply external to the vehicle.
Description of the Background Art
An electric vehicle or a hybrid vehicle is mounted with a drive battery configured to supply power to a drive motor. If the battery is not charged and/or discharged at a proper temperature, it will prevent the battery to exhibit its performance sufficiently and will adversely affect the service life thereof, and thereby, a temperature regulating device for the battery is mounted on such vehicle.
In WO 2012/004926, a battery cooling device is disclosed. The battery cooling device utilizes a refrigerant in a refrigerant circulation system for air conditioning to cool the battery.
The battery cooling device described in WO 2012/004926 mentioned above, the heat of the battery is substantially discarded through cooling. Thus, sufficient studies have not been made on making effective utilization of this heat.
Particularly, since the heat from engine cannot be utilized to warm the compartment of a hybrid vehicle when the engine thereof is stopped and the heat from engine is not available for an electric vehicle without an engine, it is necessary to convert the electrical energy that is accumulated in the battery into heat so as to warm the passenger compartment, which consequently shortens the available traveling distance. Therefore, the inventors of the present application turn to investigate another approach of warming the compartment by preheating the battery with power received from a power supply external to the vehicle when charging the battery with the power received from the external power supply (hereinafter referred to as external charging), and using the heat in the battery to warm the compartment or the like. Since the drive battery in an electric vehicle or a hybrid vehicle is large in both size and heat capacity, it is possible to utilize the battery more effectively by using it as a heat accumulation unit. Raising the temperature of the battery during external charging is advantageous from the viewpoint of increasing the available travelling distance, however, raising the temperature of the battery to the same temperature without variation during external charging is disadvantageous from the viewpoint that additional power will be consumed.